Carcinoembryonic antigen: physician attitudes, patterns of use, and impact upon patient care.

Recent data would limit indications for serum CEA measurement primarily to follow-up of resected colonic malignancy, yet physician attitude and usage patterns may lag far behind current findings. This discrepancy was investigated at our institution, where more than 1100 CEAs costing $71,000 are ordered each year. Of 45 physicians (all MDs ordering a CEA test during a preselected month), over 50% believed the test to be worthwhile in initial detection of colonic cancer, and 69% thought an elevated CEA to be an adequate reason to begin an aggressive workup to rule out cancer of the colon in a nonsmoking, previously healthy patient. Impressions of cost were less than or equal to $30 (50% of true cost) in nearly half of MDs and less than 20% of true cost in a tenth of MDs. Analysis of the medical record revealed that indications of questionable validity (initial detection of cancer together with follow-up of noncolonic malignancy) accounted for the majority of requested CEAs and included the attempted detection or monitoring of 12 different tumor types in addition to its use as a "general cancer screen." Patient benefit was realized in none in a random sample of 106 cases (beta = 0.11, power = 0.89 for an assumed benefit of 2%), while management was altered in only one patient as a direct result of the CEA value. It is important that we continue to inform and educate our colleagues about relatively expensive tests that have only limited and specific application.